Heart fatty acid-binding protein (H-FABP) is present in a wide variety
of tissues but is found in the highest concentration in cardiac and r
ed skeletal muscle. It has been proposed that the expression of H-FABP
correlates directly with the fatty acid-oxidative capacity of the tis
sue. In the present study, the expression of H-FABP was measured in re
d and white skeletal muscle under two conditions in which fatty acid u
tilization is known to be increased: streptozotocin-induced diabetes a
nd fasting. Protein concentration, mRNA concentration and transcriptio
n rate were measured under both conditions. The level of both protein
and mRNA increased approximately 2-fold under each condition. The tran
scription rate was higher in red skeletal muscle than in white muscle,
was increased 2-fold during fasting, but was unchanged by streptozoto
cin-induced diabetes. In addition to supporting the hypothesis that H-
FABP is induced during conditions of increased fatty acid utilization,
these findings demonstrate that the regulation of H-FABP expression m
ay or may not be at the level of transcription depending on the stimul
us.